I had a biology teacher that told us this story about an octopus at an aquarium in Australia. The staff were concerned because their population of crustaceans kept disappearing. No bodies or anything. So they checked the video feed to find out what’s up.

Across from the the crustacean tank was a small octopus tank. This little fucker squeezed out of a tiny hole at the top of his tank, walk across the hall, and get into the crustacean tank. He would then hunt and eat. After he was done, he crawled back out and get back in his tank

Here’s the kicker: security guards patrolled the area. The staff realized that the octopus had memorized the security’s routine. It would escape and be back between the guards’ round.